1. Genetic resistance to Salmonella typhimurium in two lines of chickens selected as resistant and sensitive on the basis of heterophil/lymphocyte ratio.
- Author
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Al-Murrani WK, Al-Rawi IK, and Raof NM
- Subjects
- Animals, Antibodies, Bacterial biosynthesis, Body Weight, Breeding, Bursa of Fabricius anatomy & histology, Chickens immunology, Female, Granulocytes cytology, Hydrocortisone blood, Immunity, Cellular, Lymphocytes cytology, Male, Organ Size, Phagocytosis, Poultry Diseases genetics, Poultry Diseases mortality, Salmonella Infections, Animal genetics, Salmonella Infections, Animal mortality, Salmonella typhimurium pathogenicity, Chickens genetics, Immunity, Innate genetics, Poultry Diseases immunology, Salmonella Infections, Animal immunology, Salmonella typhimurium immunology, Selection, Genetic
- Abstract
1. A study was conducted to test for the validity of the heterophil/lymphocyte (H/L) ratio as a criterion for selection for resistance to Salmonella typhimurium in chickens. 2. An infective dose of S. typhimurium was given, directly in the crop, to two groups of chicken selected as Resistant (R) and Sensitive (S) on the bases of H/L ratio. The 99% lower confidence limit was used as a borderline; individuals below the limit were considered R and those above S. Many aspects of immune response were compared, namely: H/L ratio, antibody titre, cellular immunity, phagocytic activity, cortisol concentration, bursa and body weight. 3. The R group exceeded the S in all the studied variables of the immune response, indicating the possibility of using the H/L ratio and its confidence limit to select for general resistance. 4. Due to the within-strain variability in resistance, it seems that immunological and genetic studies should take into consideration separation of individuals into R and S before grouping. Failing to do so might lead to erroneous conclusions as a difference may simply be due to the different numbers of R and S included in each group.
- Published
- 2002
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